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CHAPTER III 



HOW PLANTS FEED AND GROW 



Whoever will be perfect in the science of agriculture must be well acquainted 

 with the qualities of soils and plants and must not be ignorant of the various 

 climates, so that he may know what is agreeable and what is repugnant to 

 each. COLUMELLA 



22. Factors that determine the harvest. In the spring a 

 farmer carries to the field a dozen ears of seed corn and in the 

 fall brings back a harvest of perhaps thirty thousand pounds of 

 green forage, or ten thousand ripened ears. Some very impor- 

 tant things have happened between the time when the farmer 

 dropped the seed into the warm earth and the time when he 

 brought home the harvest. Where did the increase come from ? 

 Will the increase always be the same ? 



The four factors which, combined, determine the abundance 

 of the harvest are the seed, the soil, the culture, and the climate. 

 Man determines the kind of seeds he will sow, and whether or 

 not they shall inherit high producing powers. He determines 

 to a considerable extent the productiveness of the soil, and with 

 judgment and skill he regulates the processes of cultivating, 

 harvesting, and housing the crop. It is only the climate which 

 he cannot modify, but to it he may adapt his practices and 

 his plants! 



23. Old crops in new climates. It is of prime importance for 

 the farmer to know how to adapt his practices to the general 

 climate of the region and to the wide range of seasons it affords. 



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